[試題] 98上黃信炅普通化學丙期末考

看板NTU-Exam作者cary0415chen (阿祥)時間14年前 (2010/01/15 15:36)推噓4(4推 0噓 1→)

留言5則, 4人參與討論串1/1

課程名稱︰普通化學丙課程性質︰必修課程教師︰黃信炅開課學院：醫學院公衛學院開課系所︰醫技護理公衛考試日期（年月日）︰2010 1 15 考試時限（分鐘）：120 是否需發放獎勵金：是（如未明確表示，則不予發放）試題 : 1.Consider the molecular orbital energy level diagrams for O2 and NO. Which of the following is true?(2pts) I. Both moleculus are paramagnetic. II. The bond strength of O2 is greater than the bond strength of NO. III.NO is an example of a mononuclear diatomic molecule. IV. The ionization energy of NO is smaller than the ionization energy of NO^+ a) I only b) I and II c) I and IV d) II and III e) I,II, and IV 2.Which of the following has the greatest bond strength?(2pts) a)B2 b)O2^- c)CN^- d)O2^+ e)NO^- 3.Draw a molecular orbital diagram for O2 and N2. Using molecular orbital theory, explain why the removal of one electron in O2 strength bonding, while the removal of one electron in N2 weakens bonding.(6pts) 4.Silver crystallizes in a cubic closesr packed structure. The radius of silver atom is 144pm. Calculate the density of solid silver. 5.A metal crystallizes in a body-centered unit cell with an edge length of 2.00*10^2 pm. Assime the atoms in the cell touch along the cube diagonal. The percentage of empty volume in the unit cell will be:(3pts) a) 0% b) 26.0% c) 32.0% d) 68.0% e) none of these 6.Carbon tetrachloride, CCl4, has a vapor pressure of 213 torr at 40℃ and 836torr at 80℃. What is the normal boiling point of CCl4?(3pts) 7.The vapor pressure of water at 25.0℃ is 23.8torr. Determine the mass of glucose(molar mass=180g/mol) needed to add to 500.0g of water to change the vapor pressure to 23.3torr.(3pts) 8.At a given temperature, you have a mixture of benzene(vapor pressure of pure benzene=745torr) and toluene(vapor pressure of pure toluene= 290torr). The mole fraction of benzene in the vapor above the solution is 0.590. Assuming ideal behavior, caculate the mole fraction of toluene in the solution.(3pts) a) 0.213 b) 0.778 c) 0.641 d) 0.359 e) 0.590 9.The solubility of nitrogen in water is 8.21*10^-4 mol/L at 0℃ when the N2 pressure above water is 0.790atm. Calculate the Henry's law constant of N2 in units of mol/(L*atm) for Henry's law in the form C=kP, where C is the gas concentration in mol/L. Calculate the solubility of N2 in water when the partial pressure of nitrogen above water is 1.10atm at 0℃.(4pts) 10.For a reaction: aA→products, [A]0=6.0M, and the first two half-lives are 56 and 28 minutes, respectively. Calculate [A] at t=99.1 minutes. (4pts) a) 5.3M b) 11M c) 1.04M d) 0.69M e) none of them 11.The rate of the reaction O+NO2→NO+O2 was studied at a certain temperature. a.In the first set of experiments NO2 was in large excess, at a concentration of 1.0*10^13 molecules/cm^3 with the following data collected. Time(s) [O](atoms/cm^3) 0 5.0*10^9 1.0*10^-2 1.9*10^9 2.0*10^-2 6.8*10^8 3.0*10^-2 2.5*10^8 What is the order of the reaction with respect to oxygen atoms?(3pts) b.The reaction is known to be first order with respect to NO2. Determine the overall rate law and the value of the rate constant.(3pts) 12.The kinetics of the reaction A+3B→C+2D were studied and the following result obtained, where the rate law is: Δ[A] -──── = k[A]^n * [B]^m Δt For a run where [A]0=1.0*10^-3M and [B]0=5.0M, a plot of ln[A] versus t was found to give a straight line with slope=-5.0*10^-2 s^-1. For a run where [A]0=1.0*10^-3M and [B]0=10.M, a plot of ln[A] versus t was found to give a straight line with slope=-7.1*10^-2 s^-1. (i) What is the value of n?(2pts) a) 0 b) 0.5 c) 1 d) 1.5 e) 2 (ii) What is the value of m?(2pts) a) 0 b) 0.5 c) 1 d) 1.5 e) 2 (iii) Calculate the value of k(ignore units).(2pts) a) 22 b) 10 c) 50 d) 1.1 e) none of these 13.Consider the following system at equilibrium: N2+3H2→2NH3+92.94KJ Which of the following changes will shift the equilibrium to the right? (4pts) I. increasing the temperature II. decreasing the temperature III.increasing the volume IV. decreasing the volume V. removing some NH3 VI. adding some NH3 VII.removing some N2 VIIIadding some N2 14.At 35℃, K=1.6*10^-1 for the reaction 2NOCl→2NO+Cl2 Calculate the concentrations of all species at equilibrum for each of the following original mixtyres. a. 2.0mol pure NOCl in a 2.0L flask.(2pts) b. 1.0mol NOCl and 1.0mol NO in a 1.0L flask.(2pts) 15.Aspartic acid(C4H7NO4), one of the 20 essential amino acid, has two ionizable hydrogens. At 25℃, Ka1=1.38*10^-4 and Ka2=1.51*10^-10 What is the concentration of doubly ionized aspartate ions in a 0.125M aqueous solution of aspartic acid?(3pts) 16.Hydrogen cyanide gas (HCN), a powerful respiratory inhibitor, is highly toxic. It is a very weal acid(Ka=6.2*10^-10) when dissolves in water. If a 50.0mL sample of 0.100M HCN is titrated with with 0.100 NaOH, calculate the pH of the solution. a.after 8.00mL of 0.100M NaOH has been added. b.at the halfway point of the titration.(2pts) c.at the equivalence point of the titration.(2pts) 17.Consider a solution made by mixing 500.0mL of 4.0M NH3 and 500.0mL of AgNO3. Ag+reactwith NH3 to form AgNH3+ and Ag(NH3)2^+: Ag+ + NH3→AgNH3+ K1=2.1*10^3 AgNH3+ + NH3→Ag(NH3)+ K2=8.2*10^3 (i) The concentration of Ag(NH3)2+ at equilibrium.(2pts) (ii)The concentration of Ag+ at equilibrium.(2pts) 18.Predict the shift in the equilibrium position that will occur for each of the following reactions when the volume of the reaction container is increased.(4pts) a. PCl5→PCl3+Cl2 b. H2+F2→2HF 19.Identify the Lewis acid and the Lewis base in each of the following reaction.(4pts) a.Fe^3+ + 6H2O→Fe(H2O)6^3+ b.H2O +CN-→HCN+OH- 20.When a diprotic acid, H2A, is titrated with NaOH, the protons on the diprotic acid are generally removes one at at time, resulting in a pH curve that has the following generic shape:(4pts) (圖片不清楚省略) a.Notice that the plot has essentially two titration curves. If the first equizalence point occurs at 100.0mL NaOH added, what volume of NaOH added corresponds to the second equizalence point? b.If the pH at 50.0mL NaOH added is 4.0 and the pH at 150.0mL NaOH added is 8.0, determine the values Ka1 and Ka2 for the diprotic acid. 21. a.Calculate the molar solubility of AgBr in 3.0M NH3. Ksp for AgBr is 5.0*10^-13. The overall formation constant for Ag(NH3)2+ is 1.7*10^7. (3pts) b.What mass of AgBr will dissolve in 250.0mL of 3.0M NH3?(3pts) 22.The standard free energies of formation and the stander enthalpies if formation at 298K for difluoroacetylene (C2F2) and hexafluorobenzene (C6F6) are ΔGf(kJ/mol) ΔHf(kJ/mol) C2F2 191.2 241.3 C6F6 78.2 132.8 For the following reaction: C6F6→3C2F2 Calculate ΔS and K at 298K. If ΔH and ΔS do not depend on temperature, please calculate K at 1000K.(6pts) 23.Prove that for a gaseous reaction, ΔG=ΔG。+RTlnQ Π(Pproducts)^np where Q is reaction quotient, Q=─────────.(2pts) Π(Preactants)^np 24.Under standard conditions, write a balanced equation and calculate the cell potential, ΔG, and K under 25℃ for the reaction of that an acidic solution of FeSO4 is exposed to air.(6pts) 25.An excess of finely divided iron is stirred up with a solution that contains Cu^2+ ions, and the system is allowed to come to equilibrium. The solid materials are then filtered off, and eletrodes of solid copper and solid iron are inserted into the remaining solution. What is the value of the ratio [Fe^2+]/[Cu^2+] at 25℃.(2pts) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.242.200 ※ 編輯: cary0415chen 來自: 140.112.242.200 (01/15 15:37)

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a36107699

01/15 15:47, , 1^F

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※ 編輯: cary0415chen 來自: 140.112.242.200 (01/15 16:28)

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ian60702

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hana4623

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